Form for molded conduits



H. W. BASSETT.

FORM FOR MOLDED GONDUITS.

APPLICATION FILED 111311.18, 1910.

Patented M11325, 1911;.

A'TTOR E}? INVEWTQR Henry WBasse Z2.

6N m w HENRY W. BASSE'IT. 0F SEATTLE, WASHINGTON.

FORM FOR MOLDED CQ1\TIDUI']IF Epeoification of Letters Patent.

Patented Apr. 25, 11.911.

application filed March 18, 1930. Serial No. 550.247.

i 0 all whom it may concern:

Be it known that T, HENRY W. Bsssnr'r, a citizen of the United States, and resident of the city of Seattle, in the county of King and State of ll ashington, have invented certain new and useful improvements in Forms for lvlOlflQCl Conduits, of which the following a specification.

llly invention relates to an improvement in forms for molded conduits, and comprises the novel parts and combinations of parts which will he hereinafter described. and particularly described in the claims.

The object of my invention is to provide a form or mold which may be used to shape the inner surfaces of conduits which are iii-ads of such materials as cement, concrete I slightly separated from the previous section which has been completed and the conduit molded.

Hy invention is more particularly applicable to molding conduits of some size and under conditions where the conduit is accessible from the top, for instance in making a sewer or other pipe in an open cut.-

For the best use of my device the size ofthe conduit should be such as to permit passage of workmen therethrough, so as to remove the inner lining and to set up the new sections.

The particular form of mold shown is designed to make a sewer conduit which, when fully completed. is to have a segment at the bottom lined with vitrified brick, and therefore, the molded section thercoi shows a. recessed segment of a depth to receive a layer 1 of brick.

The outline ot the conduit which I have shown to illustrate my invention. is circular, althougl it will be understood that it may be modified so as to be used to mold con duits of other trausvwso outline.

in Fig. 2 will be soon. at the right. thc end. A, of the body oi a section ot conduit which has just been molded. The material which have shown my iuven-' will be assumed to have been used is concrete, although vany other material may be used which is of similar character, in respectat least, as to its adaptability to being molded to shape. In fact. some of the features of my invention may be used with advantage in building conduits out of brick or like materials of block form which are laid up as masonry.

The forms which outline the inner surface of the conduit consist of a. series of segments, 2, 3, a and 5, each segment consisting of an outer skin 20 composed of boards, longitudinal ribs, 25. and transverse ribs-21. The sections 2 and 3 are alike in constriction, but differ in the manner in which they are placed when in use.

Two sections 4 and one section f), are used in forming the part which is to receive the brick lining, The outer sections 4 have their outer edges radial. but their inner edges, as outlined by the longitudinal ribs 23, are sloping from a radius, the angle of inclination being such as to make the outer angle at this edge considerably less than a right angle. The material point is that the. opposing surfaces of the segments 4 be somewhat farther apart at their upper edges than at their lower cdgcs. The central section 5, has its side ribs 23, similarly inclined so that this segment acts as an inverted keystone, or one which may be removed from the concave side of the arch.

The various segments which outline the form are held in place at one end by engagement with the segments which have been used in molding the last section of the conduits. and at the other end they are held in place by a ring or templet 1, which is in the form of a ring or flange extending ra-. dially and about the whole. This ring acts as a restraining member to keep the seg: ments in place when forced outward, and also to determine their exact position. It also acts as a wall to determine the end sur-- face of the section being molded.

In setting the form up for a. new sectionof conduit, the ring 1 is accurately placed, then the lower segments 4 and 5 are put in place. Transverse beams or sills 6, are placed upon the transverse ribs 24;, of the outer segments 4. The segments 3, 3,"are placed in position and thenthe upper segments 2, these being held in place by placing the interior bracing consisting of the central vertical posts 7, and the radial bars v 8, which extend from the center of the conand the other side radially to fit the edgeof the segments 3.

The position of the segments 3 and 4 issuch that the segments 4 are wholly outside of, that is, farther from the center, than the segments 3, so that the segments 3 may, under certain conditions, slide over or overlap the segments 4. This occurs when first setting up the segments 2 and Also the post 7 and bars 8are cut somewhat shorter than is needed to hold the segments out against the ring or templet 1.

After the segments 2 and 3 have been put in position, wed cs 13 are driven between the ends of the $1118 6 and the edges of the segments 3, expanding the segments out ward against the ring 1. At the same time wedges 9 are driven between the bars 8 and the ribs 25 to force the segments outward against the ring 1, thus holding the whole structure firmly'in exact position. Blocks 10 are also placed between the sills 6 and the lower or invert segments 4 and 5, thus holding these securely in exact position.

The restraining member or ring 1, where it is desired to form a conduit with a lining recess, has its inner outline oflset at the mar gins of the lined section, as at the points 11, this ofi'set being of the depth of the lining to be inserted. The segments 4: and 5 which form this lined section, or the invert as herein shown, are made to fit closely against this offset, the inner segment 5 being shaped as a keystone insertible and removable from the interior. The depth of this oii'set is that of the thickness of the linin ments. These-segments are so placed that when set up, the ends of the segments forming the new section will overlap those of the section just completed, in such a way as to resist displaceinent while setting up and while placing the material of the wall, at

least until the interior bracing has been placed. In some cases the outer skin of the segments of the new section will be outside thctransversc ribs of the'segrnents of the to be inserted; An inspection of Fig. 2 wi 1 show that the preceding section, and in some cases this cond1t1on will be reversed. Also, the ends of the longitudinal ribs project half the thickness of the transverse ribs at one end and terminate at the center line of the transverse ribs at the other end, whereby the ends of the segments of adjoining sections interlock to secure exact registry and to prevent peripheral displacement. The segments of the completed section. of conduit thus support and exactly locate the segments which are set up forfrhe molding or a new section. The other ends of the segments are located and held by the encircling band or restrain i'ng member 1, which forms the end wall of the space to be filled with the conduit material.

Aftera conduit section has been molded, the bars 7 and 8 and the wedges used be tween these bars and the segments to key the latter out against the ring 1, are removed and used to set up another section. The encircling ring 1' is also moved ahead the length of 'a section and used to locate and hold the segments for the next section. The segments themselves are left within the conduit a sufiicient length of time to permit the conduit waiis to set sufiiciently, and are then taken down and removed. This method of forming the mold and using it, secures rapid and accurate work and also cheapness both in the construction of the molds and in their operation.

After the concrete has been set suiliciently to warrant removal of the segments of the mold, these may be removed and the lining to be given 1n the invert may be put in place as soon as convenient. This part of the work may be outline the invert, other longitudinal segments adapted to outline the remainder of the conduit, a restraining band adapted to surround and locate said segments andhaving its inner edge recessed to hold. the invert segments enough farther from the center than the segments adjoining to permitthe edges of the latter moving peripherally within the invert segments, and means or peripherally expanding those segments above the invert.

2. An inner form for molded conduits comprising a series of segments adapted to be assembled to act asan arch and outline the bore of the conduit, the segments of adjacent sections having complemental projections and recesses adapted to interlock to prevent displacement both radially and peripherally, a templet or rib adapted to surround the outer ends of the segments of a section to restrain them against outward rib, whereby tween segments may be obtained, said segmovement. and also to form an end wall for the mold.

3. An inner form for molded coni'luits, coni nrising a series of longitudinal segn'ients adapted, when assembled, to outline the bore 1 of the COT:(lLl1t,'ll'l endsot said segments-haw ing coinpleinental projections and recess formed by the relative positions of their outer skin and ribs, and adapted to engage to prevent displacement of the seginents of adjacent sections both in a radial and peripheral directioin a templet or partition surrounding the outer ends of the segments of the section and having its openin zcon gitudinal and transverse ribs, and an outer skin, the transverse ribs at the ends of the segments being oti'set relative to the outer skin to interlock against displacement ra dially at the junction of adjacent sections and the ends of the longitudinal ribs being oflset relative to the t 'ansverse ribs to interlock to prevent displacement peripherally between adjacent sections.

C 5. An inner form for molded conduits,

'con'iprising longitudinal segments composed oi outer lagging and ribs secured thereto, said ribs including transverse ribs at each end, the transverse rib at one end projecting beyond the ends of the lagging and at the other end the lagging extending beyond the interlocking engagement beinents also having longitudinal ribs at their side edges adapted to engage those of adjai l l l l l l l l l l 1 l l l l i i l l l l l l l l ,and having band,

A} All L form for molded consults, nents adapted to outline the invt-rtr one oi id segments being removable inwardly, another. sit of segments adapted to outline the remainder the conduit a re straining member surroinidii the segments an off-set outline Q it the edges of the invert section; whereby the adjacent segments may slide one over the other, trans verse sills spanning the invert segments and serving as an alinitnrent tor the other nients and means "for ing the segments outmirdl from said sills against the straining member.

T, An iincr form for n'iol'cled conduits, comprising segments adapted to outline the invert, one of said segments being removable inwardlv x another set of segments adapted to outline that portion of the conduit above the invert. a restraining member surrounding the s nents and having a i oft-set out.- line the edges of the invert section, wht by the segments ateach side may slide, one over the er, transverse sills spanning the invert segments a'nd serving as abutments for the upper segn'ients, means for keying said upper segments outward from said sills, and posts braced against each other and the segments at their meeting edges to hold them more securely against the restraining T116111- her.

in testimony whereof l fixed my signature at Seattle, l i zisliiiigtoii, It'liarch, 1910i v HENRY i BASSETT,

Gonnon MACMILLAN.

ve hereunto af- 

